The present invention relates to a method and a system for producing an elongated drug formulation, in particular an elongated drug formulation having sufficient strength for being injected through the skin of the patient without the use of a needle or cannula.
Some drugs are administered parenterally, either because a rapid effect is desired, or because due to the nature of the drug it will be destroyed in the stomach before any effect of the drug has occurred.
By far the most widely used method for parenteral injection of drugs is by injection of an aqueous solution using a hypodermic syringe. The use of aqueous solutions is associated with a number of inherent problems. In order to inject a given volume of drug, a much larger volume of water and different additives also have to be injected, leading to injection of a high volume. In particular for muscular injection the pain associated with injection is primarily caused by the volume injected, not by the penetration of the skin. Any reduction in volume would thus lead to a reduction in pain for the patient.
Injection of drugs as solid particles have been discussed in the prior art, such as powder injection and injection of drug formulations having the shape of needles, the latter being administerable with greater precision than the powders.
WO 96/08289 (Societe de conseils de recherches et d""application scientifiques S.A) discloses a medicament having the shape of one end of a toothpick. Its dimensions range from 1 mm to 3 cm in length. The medicament has a crush strength of 8 millipoise and is described to be prepared using conventional techniques such as compression, thermofusion, or extrusion without specifically discussing any of the techniques.
Macroneedles for injection are also disclosed in WO 96/03978 (Quadrant Holdings Cambridge Ltd). These needles are of the dimension 0.1 to 4 mm in diameter and 1 to 30 mm in length. The needles comprise a glassy vehicle and an effective amount of at least one guest substance and are prepared by extrusion.
To obtain a satisfactory solid-dose-parenteral-injection, the drug formulation to be injected must be of small volume to avoid injection pain and to achieve a desired dissolution rate. Also, the drug formulation should be provided with a well-defined strength to make it possible to penetrate the cutis of the patient, be it an animal or human being. Furthermore, the drug formulation should be long-term stable at ambient temperature in terms of both strength and structure of the drug formulation and the biological activity of the drug. The pre-determined strength may be provided by using a carrier in addition to the drug to be administered. A carrier used to provide the necessary strength should comprise compounds that are tissue compatible and that are contained in the pharmacopoeia.
Compression of a granulate consisting of active compounds and optionally vehicle substances is known from tablet pressing, whereby the granulate is metered in a cavity and subsequently compressed by entering a plunger into the cavity. Tablets are mostly pressed in the form of cylinders of relatively short length as compared to the diameter of the cylinder. The strength of the tablet is not crucial with respect to the functionality thereof since the tablet is often swallowed to be disintegrated by the body fluids and enzymes in the stomach and guts.
In order to compress the drug formulations to be parenterally injected it has been found that the usual method of tablet pressing is not applicable, possibly due to the small dimensions of the drug formulation whereby the metering process for filling the matrices is impaired. Furthermore, it may not be possible to obtain the relevant strength by the use of conventional compression technology.
Accordingly, it has been an object of the present invention to provide a method for producing an elongated drug formulation for parenteral administration.
This is achieved by the present method for producing an elongated drug formulation comprising
arranging a first roller adjacent a surface, whereby a cavity is defined between the first roller and the surface, the shape of the drug formulation being defined by the cavity,
feeding a gap between the first roller and the surface with drug granulate,
rolling the roller against the surface whereby a pressure is applied to the drug granulate and the drug formulation is formed in the cavity,
disengaging the first roller from the surface, and
releasing the compressed drug formulation from the cavity.
The term xe2x80x9celongatedxe2x80x9d is used in its usual meaning, i.e. that the length dimension is larger than the width or diameter of the drug formulation.
Furthermore, the invention relates to a system for producing an elongated drug formulation comprising a first roller arranged adjacent a surface, defining a cavity is defined between the first roller and the surface, means for feeding a gap between the first roller and the surface with drug granulate, means for rolling the roller against the surface compressing a drug formulation in the cavity, means for disengaging the first roller from the surface, and means for releasing the compressed drug formulation from the pocket cavity.